Hi Suzie

Now the place I think would be ideal is not an island but if you are able to fly from Manchester or Gatwick I would suggest you try Parga on the mainland.

It has everything you mention and is most def not 18-30 lager lout.

There are various posts on here that mention Parga (use the search at top of page) but for a quick look this link will show a couple of my pictures

http://www.holidaytruths.co.uk/search.php?st=0&sk=t&sd=d&keywords=parga&start=40

also check

http://parga.com/

and

http://www.holidaytruths.co.uk/reviews/greece/epirus/parga/

The Parga Q&A thread

http://www.holidaytruths.co.uk/viewtopic.php?f=17&t=75341&st=0&sk=t&sd=a

finally

http://www.tripadvisor.com/ShowUserReviews-g189452-r5441805-Parga_Epirus.html

Pargra has a hill that goes up to the castle and over to Lychnos beach so if their are any members of your party that have walking difficulties it would be best to find accomodation on the Parga town side.

Graham

Have a look at Argassi in Zante. We went as a large party with a variety of ages, and it was one of the best holidays we've had. You can do as little or as much as you want. It's also central for visiting other resorts. Good luck with your search.